In a recent network image communication system, image servers storing images taken by plural cameras are installed at plural positions, these image servers are connected through the Internet, and the image of each image server can be observed by a computer terminal at the center (hereinafter called client PC). This system is widely used as camera system or monitor system and the like.
FIG. 27 is a block diagram showing a conventional camera system.
In FIG. 27, the camera system is composed of image servers 702 to 705 for storing images taken by cameras, a client PC 701 observing the images of image servers as the center, and a local area network (LAN) 716 for connecting them.
The image servers 702 to 705 are identical in configuration. Each one of the image servers 702, 703, 704, and 705 has a mutually different IP address, and the user specifies the IP address, so that the client PC 701 takes in the image of the image server of the specified IP address.
The image server 702 is composed of an image server controller 706, a memory 707, a LAN interface unit 708, an image input unit 709, and an image data creator 710.
The image server controller 706 controls the entire image server 702.
The memory 707 includes an HTML data storage 7071 for storing web pages, an image data storage 7072 for storing image data taken by camera, and a user setting information storage 7073 for storing various data specified by the user.
The LAN interface unit 708 is an interface for connecting to the LAN.
The image input unit 709 receives an image signal v taken by a camera (not shown in FIG. 27) of the image server 702.
The image data creator 710 creates image data in JPEG or other formats from the image signal sent from the image input unit 709.
The LAN interface unit 708 is an interface for connecting to the LAN.
The client PC 701 includes a PC controller 711 for controlling the entire computer system, an input unit 712 for entering or manipulating various data, a display unit 713 for displaying image data from the image servers 702 to 705, a memory 714, and a LAN interface unit 715 for connecting to the LAN. Herein, the memory 714 includes a browser storage 714a for storing browser or other browsing software and the like.
The operation of the camera system is explained by referring to FIG. 28.
FIG. 28 is a flowchart showing the operation of the conventional camera system.
In FIG. 28, when the image server controller 706 judges that the signal designating the IP address is received from the client PC 701 (S141), the image server controller 706 acquires the HTML data for initial image which is the home page information from the HTML data storage 7071 of the memory 707, and transmits the data to the client PC 701 (S142). The client PC 701 requests transmission of image data according to the HTML data for initial image.
When the image server controller 706 judges that a transmission request of image data is received (S143), the image server controller 706 takes in the image data from the image data storage 7072 of the memory 707, and transmits the data to the client PC 701 (S144).
At step S143, if image data is not requested, and it is judged that transmission request of other data than image data is received from the client PC 701 (S145), the image server controller 706 takes in the requested data from the memory 707, and transmits the information according to the request to the client PC 701 (S146).
When the image server 703, 704, or 705 is accessed from the client PC 701, each image server operates in the same manner.
In the conventional camera system, if desired to display images of image servers of plural different IP addresses on the screen of the client PC 701, each one of the image servers needs to be accessed.
Specifically, from the started browser, the IP address of only one image server can be accessed, and the browsers as many as the number of image servers to be displayed needs to be started, and the IP addresses as many as the number of image servers needs to be accessed individually.
Therefore, to display images of image servers of plural different IP addresses on one screen, the exclusive browser software for arranging images of plural browsers started on the screen as desired by the user, and for observing the images of plural image servers simultaneously on the screen, needs to be installed in the client PC.
To create such exclusive software, the user is required to have an advanced professional knowledge.
Using the exclusive software, as mentioned above, it is possible to display images of image servers of plural different IP addresses on the one screen, but it is costly to create such exclusive software. If the exclusive software is not free, the user's expenses are increased.
If general public users desire to observe images of image servers of plural different IP address on one browser window screen, the images are displayed only in computers in which the exclusive software is installed, and general public users not having computer with installed exclusive software cannot observe the images of image servers.